Well, header+footer can only work, if your encoded image is exactly as long as the one you cut the header and footer off from, as resource information is stored at the end of the file... So if the offset to the resource at the beginning of the file points somewhere else because you're changing the length of the content, it won't work. The header+footer attempt probably only works well where the image isn't (RLE) encoded at all. First 4 bytes of RSR: Offset to first resource. Next 4 bytes offset to ResourceMap As it's high bytes first, resolving the address could go like that: (((adr[0]*256)+adr[1])*256+adr[2])*256+adr[3] Trying to remember what's else in there ;-9